(a) Field of the Invention
The present invention relates to a resistance generator adapted to a stationary bicycle exerciser, and more particularly, to one that generates resistance by vortex-induced magnetic loss during the cycling driven by rear wheel of the bicycle.
(b) Description of the Prior Art
Referring to FIG. 1 of the accompanying drawings, a resistance generator of the prior art is adapted to a bicycle exerciser as disclosed in U.S. Pat. No. 4,826,150 essentially comprised of a main support frame 10, a girder frame 20 each respectively connected to both ends of the main support frame 10, a telescopic shaft 30 vertically erected into the main support frame 10, and a head tube 40 connected at a certain inclination to a front wheel. When the bicycle exerciser is lifted off the ground by the telescopic shaft 30 and the head tube 40, the resistance generator 50 adapted to the rear end of the main support frame 10 contacts and is driven by a rear wheel of the bicycle exerciser to produce resistance.
As illustrated in FIG. 2, said resistance generator 50 by having provided an iron disk 502 and an aluminum disk 503 at an end of a transmission shaft 501, and multiple magnets 504 fixed to the front of said iron disk 502. Magnetic north and south poles of those magnets are interlaced with one another. Said aluminum disk 503 is placed in front of those magnets 504. Another iron disk 506 allowing micro-adjustment is provided inside an outer cover 505 on one side of the resistance generator 50, and multiple magnets 507 with their magnetic north and south poles are also fixed to the front of the iron disk 506. Both groups of magnets 504 and 507 are disposed relatively on both sides of the aluminum disk 503. Once the rear wheel cycles to drive the iron disk 502 and those magnets 504 via the transmission shaft 501, the resistance is produced due to rejection by opposite magnetism from those magnets 507.
However, the bicycle exerciser generally available in the market today consumes too much space and takes two groups of magnet to produce resistance making it a problem for use and storage and more complicate in the manufacturing process to produce the resistance generator.
The primary purpose of the present invention is to provide a resistance generator for a stationary bicycle that produces resistance by vortex magnetic loss. To achieve the purpose, the resistance generator is comprised of a support unit, a transmission unit and a magnetism-controlled unit. In the magnetism-controlled unit, multiple magnets are arranged in a circle with interlaced north and south poles on one side of a fixation disk and linked with an aluminum disk with a transmission shaft from the transmission unit. As is those magnets on the fixation disk are disposed in relation to said aluminum disk, said aluminum disk and those magnets create vortex magnetic loss to produce the resistance when a wheel is cycling to drive said aluminum disk to rotate via the transmission shaft. In turn, the resistance is generated for a rider of the stationary bicycle to achieve fitness training effects.
Another purpose of the present invention is to provide a resistance generator of a stationary bicycle with the resistance adjustable. To achieve this purpose, a right support disk is provided to the support unit and one or more than one slope is provided on the flange of the right support disk. An elastic member is provided behind the fixation disk from the magnetism-controlled unit and an ear is provided on the upper edge of said elastic member. Said ear penetrates the slope on the flange of the right support disk to be linked to a control button for adjusting the spacing between the fixation disk and the aluminum disk, thus to vary the amount of the resistance.
Another purpose yet of the present invention is to provide a resistance generator that has provided at its bottom a frame to lift the rear wheel of the stationary bicycle off the ground for the rear wheel merely contacts the transmission unit to drive the aluminum disk to rotate.